Sheet tray and image forming apparatus

ABSTRACT

A sheet tray includes: a tray body; first and second guides slidable on the tray body and contactable with a sheet; an interlocking mechanism; and a plate including first and second plate engaging portions. The first guide includes a first guide engagement portion and a first operation portion. The second guide includes a second guide engagement portion and a second operation portion. When the first operation portion and the second operation portion are located at non-operated positions, the plate is located at a first position where the first and second plate engaging portions are respectively engaged with the first and second guide engagement portions. When the first operation portion and/or the second operation portion is located at an operated position, the plate is located at a second position where the first and second plate engaging portions are respectively spaced apart from the first and second guide engagement portions.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent ApplicationNo. 2017-004469, which was filed on Jan. 13, 2017, the disclosure ofwhich is herein incorporated by reference in its entirety.

BACKGROUND

The following disclosure relates to a sheet tray configured to supportand position a sheet and to an image forming apparatus including thesheet tray.

A sheet tray is conventionally mounted on an image forming apparatussuch as a copier and a printer. The sheet tray supports a sheet to besupplied to an image forming device configured to form an image.Examples of the sheet tray include: a cassette tray accommodatable inthe image forming apparatus; and a plate-like tray mounted on a sidesurface of the image forming apparatus so as to extend obliquely. Thesheet tray is provided with at least one guide for positioning the sheetin accordance with the size of the sheet.

One example of the at least one guide is a pair of right and left sideguides configured to determine the sheet in a widthwise direction.Common side guides are slid toward and away from each other by racks anda pinion gear. Thus, when one of the side guides is slid in onedirection, the other side guide is slid in the other direction inconjunction with the movement of the one sheet guide. The one side guidehas a protrusion at its lower portion. When the protrusion is engagedwith one of grooves formed in the sheet tray, the one side guide ispositioned.

To disengage the protrusion and the groove, the one side guide isprovided with an operation portion shaped like a knob. A user slides theside guide while holding the operation portion. It is assumed that theoperation portion is principally operated with a right hand, and theoperation portion is usually provided on a right side guide viewed fromthe user operating the image forming apparatus, making it difficult fora left-handed user to operate the operation portion.

To solve this problem, in a conventional image forming apparatus, a lockmember constituted by a protrusion and an operation portion formedintegrally is detachably attached to one of right and left side guides,and this lock member is attachable to any of the side guides. Thus, auser can attach the lock member to a desired one of the side guides,depending upon his or her dominant hand.

SUMMARY

However, this configuration requires reattachment of the lock membereach time when the image forming apparatus is used by the user differentin a dominant hand from the preceding user, resulting in inconvenienceto the user. Furthermore, there is a possibility of a loss of thedetached lock member.

Accordingly, an aspect of the disclosure relates to a sheet trayprovided with a pair of interlocked guides that are slidable by anoperation an operation portion of one of the guides, and relates to animage forming apparatus including the sheet tray.

In one aspect of the disclosure, a sheet tray, comprising: a tray bodyconfigured to support a sheet; a first guide provided on the tray bodyso as to be slidable in a widthwise direction orthogonal to a sheetconveying direction in which the sheet is to be conveyed, the firstguide being contactable with a first edge portion of the sheet in thewidthwise direction to position the sheet; a second guide provided onthe tray body so as to be slidable in the widthwise direction andcontactable with a second edge portion of the sheet in the widthwisedirection to position the sheet; an interlocking mechanism configured tointerlock sliding operations of the first guide and the second guide;and a plate movably supported by the tray body and comprising (i) afirst plate engaging portion to be engaged with the first guide and (ii)a second plate engaging portion to be engaged with the second guide,wherein the first guide comprises: a first guide engagement portion tobe engaged with the first plate engaging portion; and a first operationportion configured to move the plate, wherein the second guidecomprises: a second guide engagement portion to be engaged with thesecond plate engaging portion; and a second operation portion configuredto move the plate, wherein when each of the first operation portion andthe second operation portion is located at a non-operated position, theplate is located at a first position at which the first plate engagingportion is engaged with the first guide engagement portion, and thesecond plate engaging portion is engaged with the second guideengagement portion, and wherein when at least one of the first operationportion and the second operation portion is located at an operatedposition, the plate is located at a second position at which the firstplate engaging portion is spaced apart from the first guide engagementportion, and the second plate engaging portion is spaced apart from thesecond guide engagement portion.

In another aspect of the disclosure, an image forming apparatus,comprising: a sheet tray; and an image forming device configured to forman image on a sheet, wherein the sheet tray comprises: a tray bodyconfigured to support the sheet; a first guide provided on the tray bodyso as to be slidable in a widthwise direction orthogonal to a sheetconveying direction in which the sheet is to be conveyed, the firstguide being contactable with a first edge portion of the sheet in thewidthwise direction to position the sheet; a second guide provided onthe tray body so as to be slidable in the widthwise direction andcontactable with a second edge portion of the sheet in the widthwisedirection to position the sheet; an interlocking mechanism configured tointerlock sliding operations of the first guide and the second guide;and a plate movably supported by the tray body and comprising (i) afirst plate engaging portion to be engaged with the first guide and (ii)a second plate engaging portion to be engaged with the second guide,wherein the first guide comprises: a first guide engagement portion tobe engaged with the first plate engaging portion; and a first operationportion configured to move the plate, wherein the second guidecomprises: a second guide engagement portion to be engaged with thesecond plate engaging portion; and a second operation portion configuredto move the plate, wherein when each of the first operation portion andthe second operation portion is located at a non-operated position, theplate is located at a first position at which the first plate engagingportion is engaged with the first guide engagement portion, and thesecond plate engaging portion is engaged with the second guideengagement portion, and wherein when at least one of the first operationportion and the second operation portion is located at an operatedposition, the plate is located at a second position at which the firstplate engaging portion is spaced apart from the first guide engagementportion, and the second plate engaging portion is spaced apart from thesecond guide engagement portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features, advantages, and technical and industrialsignificance of the present disclosure will be better understood byreading the following detailed description of the embodiments, whenconsidered in connection with the accompanying drawings, in which:

FIG. 1 is a simplified perspective view of an image forming apparatusaccording to one embodiment;

FIG. 2 is a perspective view of a sheet tray according to the firstembodiment, illustrating a front side thereof;

FIG. 3 is a perspective view of the sheet tray according to the firstembodiment, illustrating a rear side thereof;

FIGS. 4A and 4B are enlarged cross-sectional views taken along line A-Ain FIG. 2, wherein FIG. 4A illustrates a state in which a firstoperation portion is located at a non-operated position, and FIG. 4Billustrates a state in which a first operation portion is located at anoperated position;

FIGS. 5A and 5B are enlarged cross-sectional views taken along line B-Bin FIG. 2, wherein FIG. 5A illustrates a state in which a secondoperation portion is located at a non-operated position, and FIG. 5Billustrates a state in which a second operation portion is located at anoperated position;

FIG. 6 is a perspective view of a sheet tray according to a secondembodiment, illustrating a front side thereof;

FIGS. 7A and 7B are enlarged cross-sectional views taken along line C-Cin FIG. 6, wherein FIG. 7A illustrates a state in which a firstoperation portion is located at a non-operated position, and FIG. 7Billustrates a state in which a first operation portion is located at anoperated position;

FIGS. 8A and 8B are enlarged cross-sectional views taken along line D-Din FIG. 6, wherein FIG. 8A illustrates a state in which a secondoperation portion is located at a non-operated position, and FIG. 8Billustrates a state in which a second operation portion is located at anoperated position;

FIG. 9 is a perspective view of a sheet tray according to a thirdembodiment, illustrating a front side thereof;

FIGS. 10A and 10B are enlarged cross-sectional views taken along lineE-E in FIG. 9, wherein FIG. 10A illustrates a state in which a firstoperation portion is located at a non-operated position, and FIG. 10Billustrates a state in which a first operation portion is located at anoperated position;

FIGS. 11A and 11B are enlarged cross-sectional views taken along lineF-F in FIG. 9, wherein FIG. 11A illustrates a state in which a secondoperation portion is located at a non-operated position, and FIG. 11Billustrates a state in which a second operation portion is located at anoperated position;

FIG. 12 is a perspective view of a sheet tray according to a fourthembodiment, illustrating a front side thereof;

FIG. 13 is a perspective view of a sheet tray according to a fifthembodiment, illustrating a front side thereof;

FIG. 14 is a right side view of a plate in the fifth embodiment; FIG. 15is a perspective view of a sheet tray according to a sixth embodiment,illustrating a front side thereof; and

FIG. 16 is a perspective view of a sheet tray according to the sixthembodiment, illustrating a rear side thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, there will be described embodiments by reference to thedrawings. An image forming apparatus includes an image forming deviceconfigured to form an image on a sheet. For example, the image formingapparatus is a printer such as an ink-jet printer, a laser printer, anda thermal printer. The image forming apparatus may be a multi-functionperipheral (MFP) having a printing function, a copying function, ascanning function, and a facsimile function.

Overall Configuration of Image Forming Apparatus

FIG. 1 illustrates an image forming apparatus 1 according to oneembodiment. The image forming apparatus 1 includes an apparatus body 2,a sheet cassette 3, and a sheet tray 4. The apparatus body 2 has arectangular parallelepiped shape in FIG. 1 for simplicity. The apparatusbody 2 contains an image forming device, not illustrated, configured toform an image on a sheet supplied from the sheet cassette 3 or the sheettray 4 and convey the image-formed sheet to an output opening 21.

The sheet cassette 3 is a box capable of storing one or more sheets forimage forming, e.g., blank sheets. The sheet cassette 3 is accommodatedin a lower portion of the apparatus body 2 so as to be drawablefrontward. The sheet tray 4 supports one or more sheets for imageforming and is mounted on a rear surface of the apparatus body 2 in aninclined state. Each sheet supported on the sheet tray 4 is conveyedfrontward into the apparatus body 2, with a lower edge of the sheetserving as a leading edge.

There will be next explained the sheet trays 4 according to firstthrough sixth embodiments.

First Embodiment

In the following description, directions and sides are defined in astate in which the sheet tray 4 is placed usably as illustrated inFIG. 1. Specifically, the right and left direction is defined in a statein which the sheet tray 4 is viewed from a front side thereof. The upand down direction is directed along a line connecting between upper andlower ends of the sheet tray 4. One of opposite surfaces of the sheettray 4 along the front surface of the sheet of FIG. 2 is defined as afront surface of the sheet tray 4, and the other surface is defined as arear surface of the sheet tray 4. The front and rear direction isdirected along a line normal to the front and rear surfaces of the sheettray 4.

The sheet tray 4 includes a tray body 41, a plate 42, urging members 43,a first guide 44, a second guide 45, and an interlocking mechanism 46.

The tray body 41 is shaped like a substantially rectangular plate. Afront surface of the tray body 41 serves as a support surface 41 acapable of supporting the sheet. The tray body 41 has a first guide hole411 and a second guide hole 412. The first guide hole 411 is anelongated hole extending through the tray body 41 from the supportsurface 41 a to a rear surface of the tray body 41 and extendingstraight in the right and left direction. The first guide 44 is fittedin and guided by the first guide hole 411 in the right and leftdirection. The second guide hole 412 is an elongated hole extendingthrough the tray body 41 from the support surface 41 a to the rearsurface of the tray body 41 and extending straight in the right and leftdirection. The first guide hole 411 and the second guide hole 412 aredifferent from each other in positions in the up and down direction andthe right and left direction. The second guide 45 is fitted in andguided by the second guide hole 412 in the right and left direction.

The plate 42 is a substantially rectangular plate coupled to an upperend portion of the tray body 41. A front surface of the plate 42 isflush with the support surface 41 a of the tray body 41 and supports thesheet with the support surface 41 a.

The plate 42 is movably supported by the tray body 41. Specifically, theplate 42 and the tray body 41 are coupled to each other by hinges 47 asone example of a third hinge mechanism. Each of the hinges 47 isconstituted by (i) a pin provided on one of the plate 42 and the traybody 41 and (ii) a hole formed in the other of the plate 42 and the traybody 41, for example. The plate 42 is pivotable in the front and reardirection about the hinges 47. The configuration using the hinges 47 formoving the plate 42 facilitates designing.

The urging members 43 are attached to the respective hinges 47. Theurging members 43 urge the plate 42 in the front direction. Each of theurging members 43 may be formed of any urging material such as a springand rubber. In the present embodiment, the urging member 43 is a torsioncoil spring. Use of the urging members 43 enables the plate 42 to beurged in the front direction with a simple configuration.

The front surface of the plate 42 has engagement grooves 421 as oneexample of a first plate engaging portion for engagement with the firstguide 44 and as one example of a second plate engaging portion forengagement with the second guide 45. The engagement grooves 421 eachextending in the up and down direction are arranged in the right andleft direction. It is noted that engagement grooves as the first plateengaging portion for engagement with the first guide 44 and engagementgrooves as the second plate engaging portion for engagement with thesecond guide 45 may be formed independently of each other. It is furthernoted that holes or protrusions may be used instead of the engagementgrooves 421.

The first guide 44 is provided on the tray body 41 so as to be slidablein the widthwise direction orthogonal to a sheet conveying direction inwhich the sheet is conveyed. The first guide 44 is brought into contactwith one edge of the sheet or sheets in the widthwise direction toposition the sheet or sheets to a predetermined position. In the presentembodiment, the first guide 44 is slidable in the right and leftdirection and brought into contact with a left edge of the sheet orsheets. In the case of a plurality of the sheets, the first guide 44aligns the sheets.

The first guide 44 includes a first guide portion 441, a first guideengagement portion 442, a first connecting portion 443, a first rackportion 444, and a first operation portion 48 which are formedintegrally with each other.

The first guide portion 441 is brought into contact with the one edge ofthe sheet or sheets in the widthwise direction to position the sheet orsheets to the predetermined position. In the present embodiment, thefirst guide portion 441 is shaped like a bar extending in the up anddown direction along the support surface 41 a of the tray body 41 andthe front surface of the plate 42. The first guide engagement portion442 is a protrusion formed near an upper end of a rear surface of thefirst guide portion 441 and engageable with any of the engagementgrooves 421. When the first guide engagement portion 442 is held inengagement with one of the engagement grooves 421, the first guide 44 ispositioned.

The first connecting portion 443 is a protrusion connecting the firstguide portion 441 and the first rack portion 444 to each other. Thefirst connecting portion 443 is fitted in the first guide hole 411 andguided in the right and left direction along the first guide hole 411.With this configuration, the first guide 44 is movable in the right andleft direction.

As illustrated in FIG. 3, the first rack portion 444 is shaped like abar extending in the right and left direction along the rear surface ofthe tray body 41. The first rack portion 444 partly constitutes theinterlocking mechanism 46. A first rack gear 444 a engageable with apinion gear 461 is formed on a lower end portion of the first rackportion 444. It is noted that FIG. 3 omits illustration of teeth of thepinion gear 461 and the first rack gear 444 a for simplicity.

The first operation portion 48 is for moving the plate 42. In thepresent embodiment, the first operation portion 48 is for pushing thefront surface of the plate 42 so as to turn the plate 42 in the reardirection. FIG. 4A illustrates the first operation portion 48 located ata non-operated position. FIG. 4B illustrates the first operation portion48 located at an operated position.

The first operation portion 48 includes: a first support portion 481; afirst moving portion 482 having a first guide contact portion 482 b; ahinge 483 as one example of a first hinge mechanism; and an urgingmember 484.

The first support portion 481 includes: a first member 481A opposed tothe front surface of the plate 42 and extending frontward from a frontsurface of the first guide portion 441; and a second member 481Bextending in the right direction from a middle portion of the firstmember 481A. The first member 481A and the second member 481B are formedintegrally with each other. A front portion of the first member 481Aserves as a knob 481 a for an operation of the first operation portion48. A portion of the first guide portion 441 which is located at a rearof the second member 481B is cut out for placement of the first movingportion 482.

The first moving portion 482 is shaped like a bar and coupled to adistal end portion of the second member 481B by the hinge 483. A frontportion of the first moving portion 482 serves as a knob 482 a for anoperation of the first operation portion 48. A rear end portion of thefirst moving portion 482 is the first guide contact portion 482 bcontactable with the front surface of the plate 42. The first guidecontact portion 482 b is in contact with a first plate contact portionof the plate 42. In other words, the first guide contact portion 482 bis in contact with a portion of the plate 42 at a first contactposition. As illustrated in FIG. 2, the first plate contact portion islocated between the hinges 47 and the engagement grooves 421 in the upand down direction. This configuration makes it possible to move theplate 42 so as to disengage the engagement groove 421 and the firstguide engagement portion 442 from each other, by a small amount ofmovement of the first guide contact portion 482 b in the front and reardirection.

The hinge 483 is constituted by (i) a pin provided on one of the firstmoving portion 482 and the second member 481B and (ii) a hole formed inthe other of the first moving portion 482 and the second member 481B,for example. The first moving portion 482 is pivotable about the hinge483 in the right and left direction. The configuration using the hinge483 for moving the first moving portion 482 facilitates designing.

The urging member 484 is provided between the knob 482 a of the firstmoving portion 482 and the knob 481 a of the first support portion 481.The urging member 484 urges the knob 482 a of the first moving portion482 in the right direction. The urging member 484 may be formed of anyurging material such as a spring and rubber. In the present embodiment,the urging member 484 is a compression coil spring and supported by aprotrusion 481 b of the first member 481A. Use of the urging member 484enables the first moving portion 482 to be urged with a simpleconfiguration.

As illustrated in FIG. 4A, when the first operation portion 48 islocated at the non-operated position, that is, when the first movingportion 482 is located at the non-operated position, the plate 42 islocated at a first position at which the first guide engagement portion442 is in engagement with one of the engagement grooves 421. In thisstate, the urging member 484 urges the knob 482 a of the first movingportion 482 in the right direction, and thereby a force in a front rightdirection acts on the first guide contact portion 482 b, so that noforce is applied from the first guide contact portion 482 b to the plate42. Since the plate 42 is urged frontward by the urging members 43, thefront surface of the plate 42 is in contact with the first guide portion441, and the first guide engagement portion 442 is in engagement withone of the engagement grooves 421. Thus, when the first operationportion 48 is located at the non-operated position, the first guide 44is held in engagement with the plate 42.

As illustrated in FIG. 4B, when the first operation portion 48 islocated at the operated position, that is, when the first moving portion482 is located at the operated position, the plate 42 is located at asecond position at which the first guide engagement portion 442 isspaced apart from the engagement grooves 421. To move the firstoperation portion 48 to the operated position, a user pulls the knob 482a toward the knob 481 a in a state in which the index finger of his orher left hand is placed on the knob 481 a, and the thumb of the lefthand is placed on the knob 482 a, for example.

When the first operation portion 48 is moved from the non-operatedposition to the operated position, the knob 482 a of the first movingportion 482 is moved in the left direction against the urging force ofthe urging member 484, which turns the first guide contact portion 482 bin the rear right direction. In this movement, the first guide contactportion 482 b pushes the front surface of the plate 42 rearward, so thatthe plate 42 is moved rearward as indicated by the arrow P in FIG. 4Bagainst the urging forces of the urging members 43. This movementseparates the first guide engagement portion 442 from the engagementgroove 421. Thus, when the first operation portion 48 is located at theoperated position, the first guide 44 and the plate 42 are disengagedfrom each other. At the same time, a second guide engagement portion 452of the second guide 45 and the plate 42 are also disengaged from eachother. Accordingly, the movement of the first operation portion 48 tothe operated position disengages the first guide 44 and the plate 42from each other and disengages the second guide 45 and the plate 42 fromeach other, and in this state the first guide 44 and the second guide 45are movable in the right and left direction. Here, there will beexplained a construction for simultaneously disengaging the first guideengagement portion 442 and the engagement groove 421 from each other anddisengaging the second guide engagement portion 452 and the engagementgroove 421 from each other. As illustrated in FIG. 2, the plate 42 isconfigured to pivot relative to the tray body 41 by the hinges 47 abouta pivot axis. Since the hinges 47 are pivotably supported by the traybody 41 at a lower right end portion and a lower left end portion of theplate 42, it is considered that a direction in which the pivot axisextends coincides with a direction directed through the lower right endportion and the lower left end portion of the plate 42. In FIG. 2, it isconsidered that the direction in which the pivot axis extendssubstantially coincides with the right and left direction. In the casewhere the direction of the pivot axis is defined, the sheet tray 4 isconfigured such that the pivot axis substantially coincides with adirection of a line connecting between the position at which the firstguide engagement portion 442 is engaged with the engagement groove 421and the position at which the second guide engagement portion 452 isengaged with the engagement groove 421. This configuration of the sheettray 4 makes it possible to simultaneously disengage the first guideengagement portion 442 and the engagement groove 421 from each other anddisengage the second guide engagement portion 452 and the engagementgroove 421 from each other, thereby enabling simultaneous movement ofthe first guide 44 and the second guide 45 in the right and leftdirection.

As illustrated in FIGS. 2 and 3, the second guide 45 is provided on thetray body 41 so as to be slidable in the widthwise direction. The secondguide 45 is brought into contact with the other edge of the sheet orsheets in the widthwise direction to position the sheet or sheets to thepredetermined position. In the present embodiment, the second guide 45is slidable in the right and left direction and brought into contactwith a right edge of the sheet or sheets. In the case of a plurality ofthe sheets, the second guide 45 aligns the sheets.

The second guide 45 includes a second guide portion 451, the secondguide engagement portion 452, a second connecting portion 453, a secondrack portion 454, and a second operation portion 49 which are formedintegrally with each other.

As illustrated in FIG. 3, the second connecting portion 453 and thesecond rack portion 454 of the second guide 45 are located on a downside of the first connecting portion 443 and the first rack portion 444of the first guide 44 in the up and down direction by an amountcorresponding to the diameter of the pinion gear 461. A second rack gear454 a engageable with the pinion gear 461 is formed on an upper endportion of the second rack portion 454. FIG. 3 omits illustration ofteeth of the second rack gear 454 a for simplicity.

The second guide portion 451, the second guide engagement portion 452,and the second operation portion 49 of the second guide 45 in FIGS. 5Aand 5B are symmetrical to the components of the first guide 44 in theright and left direction, and a detailed explanation thereof isdispensed with. FIG. 5A illustrates the second operation portion 49located at a non-operated position. FIG. 5B illustrates the secondoperation portion 49 located at an operated position. It is noted thatreference numerals corresponding to those of the components of the firstoperation portion 48 in FIGS. 4A and 4B are used for components of thesecond operation portion 49 in FIGS. 5A and 5B. The second operationportion 49 includes: a second support portion 491; a second movingportion 492 having a second guide contact portion 492 b; a hinge 493 asone example of a second hinge mechanism; and an urging member 494. Thehinge 493 is constituted by (i) a pin provided on one of the secondmoving portion 492 and a second member 491B of the second supportportion 491 and (ii) a hole formed in the other of the second movingportion 492 and the second member 491B, for example. The second movingportion 492 is pivotable in the right and left direction about the hinge493.

As illustrated in FIG. 5A, when the second operation portion 49 islocated at the non-operated position, that is, when the second movingportion 492 is located at the non-operated position, the plate 42 islocated at the first position at which the second guide engagementportion 452 is in engagement with one of the engagement grooves 421. Inthis state, the urging member 494 urges a knob 492 a of the secondmoving portion 492 in the left direction, and thereby a force in a frontright direction acts on the second guide contact portion 492 b, so thatno force is applied from the second guide contact portion 492 b to theplate 42. Since the plate 42 is urged frontward by the urging members43, the front surface of the plate 42 is in contact with the secondguide portion 451, and the second guide engagement portion 452 is inengagement with one of the engagement grooves 421. Thus, when the secondoperation portion 49 is located at the non-operated position, the secondguide 45 is held in engagement with the plate 42.

As illustrated in FIG. 5B, when the second operation portion 49 islocated at the operated position, that is, when the second movingportion 492 is located at the operated position, the plate 42 is locatedat the second position at which the second guide engagement portion 452is spaced apart from the engagement grooves 421. To move the secondoperation portion 49 to the operated position, the user pulls the knob492 a toward a knob 491 a in a state in which the index finger of his orher right hand is placed on the knob 491 a, and the thumb of the righthand is placed on the knob 492 a, for example.

When the second operation portion 49 is moved from the non-operatedposition to the operated position, the knob 492 a of the second movingportion 492 is moved in the right direction against the urging force ofthe urging member 494, which turns the second guide contact portion 492b in the rear left direction. In this movement, the second guide contactportion 492 b pushes the front surface of the plate 42 rearward, so thatthe plate 42 is moved rearward as indicated by the arrow P in FIG. 5Bagainst the urging forces of the urging members 43. This movementseparates the second guide engagement portion 452 from the engagementgroove 421. Thus, when the second operation portion 49 is located at theoperated position, the second guide 45 and the plate 42 are disengagedfrom each other. At the same time, the first guide engagement portion442 of the first guide 44 and the plate 42 are also disengaged from eachother. Accordingly, the movement of the second operation portion 49 tothe operated position disengages the second guide 45 and the plate 42from each other and disengages the first guide 44 and the plate 42 fromeach other, and in this state the second guide 45 and the first guide 44are movable in the right and left direction.

The interlocking mechanism 46 enables interlocked sliding operations ofthe first guide 44 and the second guide 45. The interlocking mechanism46 is constituted by the pinion gear 461 provided on the rear surface ofthe tray body 41, and the first rack portion 444 and the second rackportion 454 arranged on the rear surface of the tray body 41.

When the first rack portion 444 is moved in the right direction, asillustrated in FIG. 3, the pinion gear 461 is rotated in thecounterclockwise direction when viewed from a rear side thereof. Thisrotation of the pinion gear 461 moves the second rack portion 454 in theleft direction. When the first rack portion 444 is moved in the leftdirection, the pinion gear 461 is rotated in the counterclockwisedirection when viewed from a front side thereof. This rotation of thepinion gear 461 moves the second rack portion 454 in the rightdirection. On the other hand, movement of the second rack portion 454 inthe right direction moves the first rack portion 444 in the leftdirection, and movement of the second rack portion 454 in the leftdirection moves the first rack portion 444 in the right direction.

It is noted that the interlocking mechanism is not limited to amechanism using a rack and pinion and may be a mechanism using an arm ora belt, for example.

In view of the above, when at least one of the first operation portion48 and the second operation portion 49 is located at the operatedposition, the first guide 44 and the plate 42 are disengaged from eachother, and the second guide 45 and the plate 42 are also disengaged fromeach other. Accordingly, when at least one of the first operationportion 48 and the second operation portion 49 is located at theoperated position, the first guide 44 and the second guide 45 aremovable in the right and left direction.

In the sheet tray 4 configured as described above, when each of thefirst operation portion 48 and the second operation portion 49 islocated at the non-operated position, the plate 42 is located at thefirst position at which the first guide engagement portion 442 is inengagement with one of the engagement grooves 421, and the second guideengagement portion 452 is in engagement with one of the engagementgrooves 421. On the other hand, when at least one of the first operationportion 48 and the second operation portion 49 is located at theoperated position, the plate 42 is located at the second position atwhich the first guide engagement portion 442 is spaced apart from theengagement grooves 421, and the second guide engagement portion 452 isspaced apart from the engagement grooves 421.

With this configuration, when at least one of the first operationportion 48 and the second operation portion 49 is operated, the plate 42engaged with the first guide 44 and the second guide 45 is moved todisengage the plate 42 and each of the first guide 44 and the secondguide 45 from each other, thereby allowing the first guide 44 and thesecond guide 45 to move in the right and left direction. Accordingly,the user may operate any of the first operation portion 48 and thesecond operation portion 49 to move both of the first guide 44 and thesecond guide 45 to their respective desired positions, resulting in highusability.

Second Embodiment

FIG. 6 illustrates a front-side configuration of a sheet tray 5according to a second embodiment. The rear-side configuration of thesheet tray 5 is similar to that of the sheet tray 4 according to thefirst embodiment (i.e., the rack and pinion), and illustration of therear-side configuration of the sheet tray 5 is omitted. The followingdescription is provided only for a difference between the sheet tray 5according to the second embodiment and the sheet tray 4 according to thefirst embodiment. Also, the same reference numerals as used in the firstembodiment are used to designate the corresponding elements of thesecond embodiment, and an explanation of which is dispensed with.

The sheet tray 5 includes the tray body 41, the plate 42, the urgingmembers 43, a first guide 54, a second guide 55, and the interlockingmechanism 46.

The first guide 54 includes the first guide portion 441, the first guideengagement portion 442, the first connecting portion 443, the first rackportion 444, and a first operation portion 58 which are formedintegrally with each other.

The first operation portion 58 is for moving the plate 42. In thepresent embodiment, the first operation portion 58 is for pushing thefront surface of the plate 42 so as to turn the plate 42 in the reardirection. FIG. 7A illustrates the first operation portion 58 located ata non-operated position. FIG. 7B illustrates the first operation portion58 located at an operated position.

The first operation portion 58 includes: a first support portion 581; afirst moving portion 582 having a first guide contact portion 582 b; afirst sliding mechanism 583; and urging members 584, 585.

The first support portion 581 includes: a first member 581A opposed tothe front surface of the plate 42 and extending frontward from the frontsurface of the first guide portion 441; and a second member 581Bextending in the right direction from a middle portion of the firstmember 581A. The first member 581A and the second member 581B are formedintegrally with each other. The second member 581B provided on the firstmember 581A is shaped like a substantially triangular prism. A rearsurface of the second member 581B is inclined such that a right portionof the rear surface is located on a front side of a left portion of therear surface. The second member 581B is one element of the first slidingmechanism 583. A front portion of the first member 581A serves as a knob581 a for an operation of the first operation portion 58. A portion ofthe first guide portion 441 which is located at a rear of the secondmember 581B is cut out for placement of the first moving portion 582.

The first moving portion 582 is shaped like a bar having three holes582A, 582B, 582C each formed through the first moving portion 582 in theright and left direction and elongated in the front and rear direction.The hole 582B is one element of the first sliding mechanism 583. Aportion of the first moving portion 582 which defines a rear end of thehole 582B is inclined along an inclined surface of the second member581B. When the second member 581B is inserted into the hole 582B, theinclined surfaces of the portion of the first moving portion 582 and thesecond member 581B are slid on each other. That is, the first movingportion 582 is slidable relative to the second member 581B.Specifically, the first moving portion 582 is movable toward the firstmember 581A in a state in which the first moving portion 582 and thefirst member 581A are parallel with each other.

A front portion of the first moving portion 582 serves as a knob 582 afor an operation of the first operation portion 58. A rear end portionof the first moving portion 582 is the first guide contact portion 582 bcontactable with the front surface of the plate 42. The first guidecontact portion 582 b is in contact with the first plate contact portionof the plate 42. As illustrated in FIG. 6, the first plate contactportion is located between the hinges 47 and the engagement grooves 421in the up and down direction. This configuration makes it possible tomove the plate 42 so as to disengage the engagement groove 421 and thefirst guide engagement portion 442 from each other, by a small amount ofmovement of the first guide contact portion 582 b in the front and reardirection.

The first sliding mechanism 583 is constituted by the second member 581Band the hole 582B. The first moving portion 582 is slidable by the firstsliding mechanism 583 in the rear left direction and the front rightdirection. This embodiment uses the first sliding mechanism 583 formoving the first moving portion 582, whereby a small amount of operationfor moving the first moving portion 582 is enough to move the plate 42by a sufficient amount.

The urging members 584, 585 are provided between the first movingportion 582 and the first member 581A. Each of the urging members 584,585 urges the first moving portion 582 in the right direction. Each ofthe urging members 584, 585 may be formed of any urging material such asa spring and rubber. In the present embodiment, the urging members 584,585 are compression coil springs and respectively supported byprotrusions 581 b, 581 c of the first member 581A. The protrusions 581b, 581 c are inserted in the respective holes 582A, 582C of the firstmoving portion 582. Use of the urging members 584, 585 enables the firstmoving portion 582 to be urged with a simple configuration. It is notedthat at least one of the urging members 584, 585 is needed.

As illustrated in FIG. 7A, when the first operation portion 58 islocated at the non-operated position, the plate 42 is located at thefirst position at which the first guide engagement portion 442 is inengagement with one of the engagement grooves 421. In this state, eachof the urging members 584, 585 urges the first moving portion 582 in theright direction, and no force acts on the first moving portion 582 inthe front and rear direction, so that no force is applied from the firstguide contact portion 582 b to the plate 42. Since the plate 42 is urgedfrontward by the urging members 43, the front surface of the plate 42 isin contact with the first guide portion 441, and the first guideengagement portion 442 is in engagement with one of the engagementgrooves 421. Thus, when the first operation portion 58 is located at thenon-operated position, the first guide 54 is held in engagement with theplate 42.

As illustrated in FIG. 7B, when the first operation portion 58 islocated at the operated position, the plate 42 is located at the secondposition at which the first guide engagement portion 442 is spaced apartfrom the engagement grooves 421. To move the first operation portion 58to the operated position, the user pulls the knob 582 a toward the knob581 a in a state in which the index finger of his or her left hand isplaced on the knob 581 a, and the thumb of the left hand is placed onthe knob 582 a, for example.

When the first operation portion 58 is moved from the non-operatedposition to the operated position, the knob 582 a of the first movingportion 582 is moved in the rear left direction against the urgingforces of the urging members 584, 585, which moves the first guidecontact portion 582 b in the rear left direction. In this movement, thefirst guide contact portion 582 b pushes the front surface of the plate42 rearward, so that the plate 42 is moved rearward as indicated by thearrow P in FIG. 7B against the urging forces of the urging members 43.This movement separates the first guide engagement portion 442 from theengagement groove 421. Thus, when the first operation portion 58 islocated at the operated position, the first guide 54 and the plate 42are disengaged from each other. At the same time, a second guideengagement portion 552 of the second guide 55 and the plate 42 are alsodisengaged from each other. Accordingly, the movement of the firstoperation portion 58 to the operated position disengages the first guide54 and the plate 42 from each other and disengages the second guide 55and the plate 42 from each other, and in this state the first guide 54and the second guide 55 are movable in the right and left direction.

As illustrated in FIG. 6, the second guide 55 includes the second guideportion 451, the second guide engagement portion 452, the secondconnecting portion 453, the second rack portion 454, and a secondoperation portion 59 which are formed integrally with each other.

A second guide portion 551, the second guide engagement portion 452, andthe second operation portion 59 of the second guide 55 in FIGS. 8A and8B are symmetrical to the components of the first guide 54 in the rightand left direction, and a detailed explanation thereof is dispensedwith. FIG. 8A illustrates the second operation portion 59 located at anon-operated position. FIG. 8B illustrates the second operation portion59 located at an operated position. It is noted that reference numeralscorresponding to those of the components of the first operation portion58 in FIGS. 7A and 7B are used for components of the second operationportion 59 in FIGS. 8A and 8B. The second operation portion 59 includes:a second support portion 591; a second moving portion 592 having asecond guide contact portion 592 b; a second sliding mechanism 593; andurging members 594, 595.

As illustrated in FIG. 8A, when the second operation portion 59 islocated at the non-operated position, the plate 42 is located at thefirst position at which the second guide engagement portion 452 is inengagement with one of the engagement grooves 421. In this state, eachof the urging members 594, 595 urges the second moving portion 592 inthe left direction, and thereby no force acts on the second movingportion 592 in the front and rear direction, so that no force is appliedfrom the second guide contact portion 592 b to the plate 42. Since theplate 42 is urged frontward by the urging members 43, the front surfaceof the plate 42 is in contact with the second guide portion 451, and thesecond guide engagement portion 452 is in engagement with one of theengagement grooves 421. Thus, when the second operation portion 59 islocated at the non-operated position, the second guide 55 is held inengagement with the plate 42.

As illustrated in FIG. 8B, when the second operation portion 59 islocated at the operated position, the plate 42 is located at the secondposition at which the second guide engagement portion 452 is spacedapart from the engagement grooves 421. To move the second operationportion 59 to the operated position, the user pulls a knob 592 a towarda knob 591 a in a state in which the index finger of his or her righthand is placed on the knob 591 a, and the thumb of the right hand isplaced on the knob 592 a, for example.

When the second operation portion 59 is moved from the non-operatedposition to the operated position, the knob 592 a of the second movingportion 592 is moved in the rear right direction against the urgingforces of the urging members 584, 585, which moves the second guidecontact portion 592 b in the rear right direction. In this movement, thesecond guide contact portion 592 b pushes the front surface of the plate42 rearward, so that the plate 42 is moved rearward as indicated by thearrow P in FIG. 8B against the urging forces of the urging members 43.This movement separates the second guide engagement portion 452 from theengagement groove 421. Thus, when the second operation portion 59 islocated at the operated position, the second guide 55 and the plate 42are disengaged from each other. At the same time, the first guideengagement portion 442 of the first guide 54 and the plate 42 are alsodisengaged from each other. Accordingly, the movement of the secondoperation portion 59 to the operated position disengages the secondguide 55 and the plate 42 from each other and disengages the first guide54 and the plate 42 from each other, and in this state the second guide55 and the first guide 54 are movable in the right and left direction.

In view of the above, when at least one of the first operation portion58 and the second operation portion 59 is located at the operatedposition, the first guide 54 and the plate 42 are disengaged from eachother, the second guide 55 and the plate 42 are also disengaged fromeach other. Accordingly, when at least one of the first operationportion 58 and the second operation portion 59 is located at theoperated position, the first guide 54 and the second guide 55 aremovable in the right and left direction.

In the sheet tray 5 configured as described above, when each of thefirst operation portion 58 and the second operation portion 59 islocated at the non-operated position, the plate 42 is located at thefirst position at which the first guide engagement portion 442 is inengagement with one of the engagement grooves 421, and the second guideengagement portion 452 is in engagement with one of the engagementgrooves 421. On the other hand, when at least one of the first operationportion 58 and the second operation portion 59 is located at theoperated position, the plate 42 is located at the second position atwhich the first guide engagement portion 442 is spaced apart from theengagement grooves 421, and the second guide engagement portion 452 isspaced apart from the engagement grooves 421.

With this configuration, when at least one of the first operationportion 58 and the second operation portion 59 is operated, the plate 42engaged with the first guide 54 and the second guide 55 is moved todisengage the plate 42 and each of the first guide 54 and the secondguide 55 from each other, thereby allowing the first guide 54 and thesecond guide 55 to move in the right and left direction. Accordingly,the user may operate any of the first operation portion 58 and thesecond operation portion 59 to move both of the first guide 54 and thesecond guide 55 to their respective desired positions, resulting in highusability.

Third Embodiment

FIG. 9 illustrates a front-side configuration of a sheet tray 6according to a third embodiment. The rear-side configuration of thesheet tray 5 is similar to that of the sheet tray 4 according to thefirst embodiment (i.e., the rack and pinion), and illustration of therear-side configuration of the sheet tray 6 is omitted. The followingdescription is provided only for a difference between the sheet tray 6according to the third embodiment and the sheet tray 5 according to thesecond embodiment. Also, the same reference numerals as used in thesecond embodiment are used to designate the corresponding elements ofthe third embodiment, and an explanation of which is dispensed with.

The sheet tray 6 includes the tray body 41, a plate 62, the urgingmembers 43, a first guide 64, a second guide 65, and the interlockingmechanism 46.

The plate 62 is a substantially rectangular plate coupled to the upperend portion of the tray body 41. The front surface of the plate 42 isflush with the support surface 41 a of the tray body 41 and supports thesheet or sheets with the support surface 41 a.

The plate 62 is movably supported by the tray body 41. Specifically, theplate 62 and the tray body 41 are coupled to each other by the hinges47. Each of the hinges 47 is constituted by (i) a pin provided on one ofthe plate 62 and the tray body 41 and (ii) a hole formed in the other ofthe plate 62 and the tray body 41, for example. This constructionenables the plate 62 to pivot relative to the tray body 41 about an axisextending in the right and left direction.

A rear surface of the plate 62 has engagement grooves 621 as anotherexample of the first plate engaging portion to be engaged with the firstguide 64 and as another example of the second plate engaging portion tobe engaged with the second guide 65. The engagement grooves 621 eachextending in the up and down direction are arranged in the right andleft direction. It is noted that engagement grooves as the first plateengaging portion for engagement with the first guide 64 and engagementgrooves as the second plate engaging portion for engagement with thesecond guide 65 may be formed independently of each other. It is furthernoted that holes or protrusions may be used instead of the engagementgrooves 621.

The first guide 64 is provided on the tray body 41 so as to be slidablein the widthwise direction. The first guide 64 is brought into contactwith one edge of the sheet or sheets in the widthwise direction toposition the sheet or sheets to the predetermined position. In thepresent embodiment, the first guide 64 is slidable in the right and leftdirection and brought into contact with the left edge of the sheet orsheets.

The first guide 64 includes a first guide portion 641, a first guideengagement portion 642, the first connecting portion 443, the first rackportion 444, and a first operation portion 68 which are formedintegrally with each other.

The first guide portion 641 is brought into contact with the one edge ofthe sheet or sheets in the widthwise direction to position the sheet orsheets to the predetermined position. In the present embodiment, thefirst guide portion 641 is shaped like a bent bar extending in the upand down direction along the support surface 41 a of the tray body 41and the rear surface of the plate 62. The first guide engagement portion642 is a protrusion formed near an upper end of the first guide portion641 and engageable with any of the engagement grooves 621. When thefirst guide engagement portion 642 is held in engagement with one of theengagement grooves 621, the first guide 64 is positioned.

The first operation portion 68 is for moving the plate 62. In thepresent embodiment, the first operation portion 68 is moved away from afront surface of the plate 62 to turn the plate 62 in the frontdirection. FIG. 10A illustrates the first operation portion 68 locatedat a non-operated position. FIG. 10B illustrates the first operationportion 68 located at an operated position.

The first operation portion 68 includes: a first support portion 681; afirst moving portion 682 having a first guide contact portion 682 b; afirst sliding mechanism 683; and urging members 684, 685.

The first support portion 681 includes: a first member 681A opposed tothe front surface of the plate 42 and extending frontward from a frontsurface of the first guide portion 641; and a second member 681Bextending upward from a middle portion of the first member 681A. Thefirst member 681A and the second member 681B are formed integrally witheach other. The second member 681B provided on the first member 681A isshaped like a substantially triangular prism. A rear surface of thesecond member 681B is inclined such that a lower portion of the frontsurface is located on a front side of an upper portion of the frontsurface. The second member 681B is one element of the first slidingmechanism 683. A front portion of the first member 681A serves as a knob681 a for an operation of the first operation portion 68.

The first moving portion 682 is shaped like a bar having three holes682A, 682B, 682C each formed through the first moving portion 682 in theup and down direction and elongated in the front and rear direction. Thehole 682B is one element of the first sliding mechanism 683. A portionof the first moving portion 682 which defines a front end of the hole682B is inclined along an inclined surface of the second member 681B.When the second member 681B is inserted into the hole 682B, the inclinedsurfaces of the portion of the first moving portion 682 and the secondmember 681B are slid on each other. That is, the first moving portion682 is slidable relative to the second member 681B. Specifically, thefirst moving portion 682 is movable toward the first member 681A in astate in which the first moving portion 682 and the first member 681Aare parallel with each other.

A front portion of the first moving portion 682 serves as a knob 682 afor an operation of the first operation portion 68. A rear end portionof the first moving portion 682 is the first guide contact portion 682 bcontactable with the front surface of the plate 62. The first guidecontact portion 682 b is in contact with the first plate contact portionof the plate 62. As illustrated in FIG. 9, the first plate contactportion is located between the hinges 47 and the engagement grooves 621in the up and down direction. This configuration makes it possible tomove the plate 62 so as to disengage the engagement groove 621 and thefirst guide engagement portion 642 from each other, by a small amount ofmovement of the first guide contact portion 682 b in the front and reardirection.

The first sliding mechanism 683 is constituted by the second member 681Band the hole 682B. The first moving portion 682 is slidable by the firstsliding mechanism 683 in the rear up direction and the front downdirection. This embodiment uses the first sliding mechanism 683 formoving the first moving portion 682, whereby a small amount of operationfor moving the first moving portion 682 is enough to move the plate 42by a sufficient amount.

The urging members 684, 685 are provided between the first movingportion 682 and the first member 681A. Each of the urging members 684,685 urges the first moving portion 682 in the up direction. Each of theurging members 684, 685 may be formed of any urging material such as aspring and rubber. In the present embodiment, the urging members 684,685 are compression coil springs and respectively supported byprotrusions 681 b, 681 c of the first member 681A. The protrusions 681b, 681 c are inserted in the respective holes 682A, 682C of the firstmoving portion 682. Use of the urging members 684, 685 enables the plate42 to be urged with a simple configuration. It is noted that at leastone of the urging members 684, 685 is needed.

As illustrated in FIG. 10A, when the first operation portion 68 islocated at the non-operated position, the plate 62 is located at thefirst position at which the first guide engagement portion 642 is inengagement with one of the engagement grooves 621. In this state, eachof the urging members 684, 685 urges the first moving portion 682 in theup direction, whereby the first moving portion 682 is secured at aposition spaced apart from the first member 681A, and the first guidecontact portion 682 b pushes the front surface of the plate 62. Whilethe plate 62 is urged by the urging members 43 in the front direction,the urging force of the urging members 43 is less than a force by whichthe plate 62 is pushed by the first moving portion 682 and the secondmoving portion 692. Thus, the rear surface of the plate 62 is in contactwith the first guide portion 641, and the first guide engagement portion642 is held in engagement with one of the engagement grooves 621.Accordingly, when the first operation portion 68 is located at thenon-operated position, the first guide 64 is held in engagement with theplate 62.

As illustrated in FIG. 10B, when the first operation portion 68 islocated at the operated position, the plate 62 is located at the secondposition at which the first guide engagement portion 642 is spaced apartfrom the engagement grooves 621. To move the first operation portion 68to the operated position, the user pulls the knob 682 a toward the knob681 a in a state in which the thumb of his or her left hand is placed onthe knob 681 a, and the index finger of the left hand is placed on theknob 682 a, for example.

When the first operation portion 68 is moved from the non-operatedposition to the operated position, the knob 682 a of the first movingportion 682 is moved in the down direction against the urging forces ofthe urging members 684, 685, which moves the first guide contact portion682 b in the front down direction. That is, the first guide contactportion 682 b is moved away from the front surface of the plate 62. As aresult, the plate 62 is turned frontward as indicated by the arrow P inFIG. 10B by the urging forces of the urging members 43. This movementseparates the first guide engagement portion 642 from the engagementgroove 621. Thus, when the first operation portion 68 is located at theoperated position, the first guide 64 and the plate 62 are disengagedfrom each other. At the same time, a second guide engagement portion 652of the second guide 65 and the plate 62 are also disengaged from eachother. Accordingly, the movement of the first operation portion 68 tothe operated position disengages the first guide 64 and the plate 62from each other and disengages the second guide 65 and the plate 62 fromeach other, and in this state the first guide 64 and the second guide 65are movable in the right and left direction.

As illustrated in FIG. 9, the second guide 65 is provided on the traybody 41 so as to be slidable in the widthwise direction. The secondguide 65 is brought into contact with the other edge of the sheet orsheets in the widthwise direction to position the sheet or sheets to thepredetermined position. In the present embodiment, the second guide 65is slidable in the right and left direction and brought into contactwith the right edge of the sheet or sheets.

The second guide 65 includes a second guide portion 651, the secondguide engagement portion 652, the second connecting portion 453, thesecond rack portion 454, and a second operation portion 69 which areformed integrally with each other.

The second guide portion 651, the second guide engagement portion 652,and the second operation portion 69 of the second guide 65 in FIGS. 11Aand 11B are symmetrical to the components of the first guide 64 in theright and left direction, and a detailed explanation thereof isdispensed with. FIG. 11A illustrates the second operation portion 69located at a non-operated position. FIG. 11B illustrates the secondoperation portion 69 located at an operated position. It is noted thatreference numerals corresponding to those of the components of the firstoperation portion 68 in FIGS. 10A and 10B are used for components of thesecond operation portion 69 in FIGS. 11A and 11B. The second operationportion 69 includes: a second support portion 691; a second movingportion 692 having a second guide contact portion 692 b; a secondsliding mechanism 693; and urging members 694, 695.

As illustrated in FIG. 11A, when the second operation portion 59 islocated at the non-operated position, the plate 62 is located at thefirst position at which the second guide engagement portion 652 is inengagement with one of the engagement grooves 621. In this state, eachof the urging members 694, 695 urges the second moving portion 692 inthe up direction, whereby the second moving portion 692 is secured at aposition spaced apart from the first member 691A, and the second guidecontact portion 692 b pushes the front surface of the plate 62. Whilethe plate 62 is urged by the urging members 43 in the front direction,the urging force of the urging members 43 is less than a force by whichthe plate 62 is pushed by the first moving portion 682 and the secondmoving portion 692. Thus, the rear surface of the plate 62 is in contactwith the second guide portion 651, and the second guide engagementportion 652 is held in engagement with one of the engagement grooves621. Accordingly, when the second operation portion 69 is located at thenon-operated position, the second guide 65 is held in engagement withthe plate 62.

As illustrated in FIG. 11B, when the second operation portion 69 islocated at the operated position, the plate 62 is located at the secondposition at which the second guide engagement portion 652 is spacedapart from the engagement grooves 621. To move the second operationportion 69 to the operated position, the user pulls a knob 692 a towarda knob 691 a in a state in which the thumb of his or her right hand isplaced on the knob 691 a, and the index finger of the right hand isplaced on the knob 692 a.

When the second operation portion 69 is moved from the non-operatedposition to the operated position, the knob 692 a of the second movingportion 692 is moved in the front down direction against the urgingforces of the urging members 694, 695, which moves the second guidecontact portion 692 b in the front down direction. That is, the secondguide contact portion 692 b is moved away from the front surface of theplate 62. As a result, the plate 62 is turned frontward as indicated bythe arrow P in FIG. 11B by the urging forces of the urging members 43.This movement separates the second guide engagement portion 652 from theengagement groove 621. Thus, when the second operation portion 69 islocated at the operated position, the second guide 65 and the plate 62are disengaged from each other. At the same time, the first guideengagement portion 642 of the first guide 64 and the plate 62 are alsodisengaged from each other. Accordingly, the movement of the secondoperation portion 69 to the operated position disengages the secondguide 65 and the plate 62 from each other and disengages the first guide64 and the plate 62 from each other, and in this state the second guide65 and the first guide 64 are movable in the right and left direction.

In view of the above, when at least one of the first operation portion68 and the second operation portion 69 is located at the operatedposition, the first guide 64 and the plate 62 are disengaged from eachother, and the second guide 65 and the plate 62 are also disengaged fromeach other. Accordingly, when at least one of the first operationportion 68 and the second operation portion 69 is located at theoperated position, the first guide 64 and the second guide 65 aremovable in the right and left direction.

In the sheet tray 6 configured as described above, each of the firstoperation portion 68 and the second operation portion 69 is located atthe non-operated position, the plate 62 is located at the first positionat which the first guide engagement portion 642 is in engagement withone of the engagement grooves 621, and the second guide engagementportion 652 is in engagement with one of the engagement grooves 621. Onthe other hand, when at least one of the first operation portion 68 andthe second operation portion 69 is located at the operated position, theplate 62 is located at the second position at which the first guideengagement portion 642 is spaced apart from the engagement grooves 621,and the second guide engagement portion 652 is spaced apart from theengagement grooves 621.

With this configuration, when at least one of the first operationportion 68 and the second operation portion 69 is operated, the plate 62engaged with the first guide 64 and the second guide 65 is moved todisengage the plate 62 and each of the first guide 64 and the secondguide 65 from each other, thereby allowing the first guide 64 and thesecond guide 65 to move in the right and left direction. Accordingly,the user may operate any of the first operation portion 68 and thesecond operation portion 69 to move both of the first guide 64 and thesecond guide 65 to their respective desired positions, resulting in highusability.

Fourth Embodiment

FIG. 12 illustrates a front-side configuration of a sheet tray 7according to a fourth embodiment. The following description is providedonly for a difference between the sheet tray 7 according to the fourthembodiment and the sheet tray 4 according to the first embodiment. Also,the same reference numerals as used in the first embodiment are used todesignate the corresponding elements of the fourth embodiment, and anexplanation of which is dispensed with.

In the first embodiment, the plate 42 and the tray body 41 are coupledto each other by the hinges 47 as one example of the third hingemechanism. In the fourth embodiment, in contrast, a plate 72 and a traybody 71 are coupled to each other by hinges 77 as another example ofthird hinge mechanism. The hinges 77 are the same as the hinges 47 inconstruction. That is, each of the hinges 77 is constituted by (i) a pinprovided on one of the plate 72 and the tray body 71 and (ii) a holeformed in the other of the plate 72 and the tray body 71, for example.The hinges 77 are different from the hinges 47 in position and providednear an upper end portion of the sheet tray 7. Thus, the plate 72 ispivotable about an axis near the upper end portion of the sheet tray 7.Due to the positions of the hinges 77, the dimension of the plate 72 isless than that of the tray body 71 in the right and left direction.Right and left end portions of the tray body 71 extend respectivelyalong right and left end portions of the plate 72. An upper end of theplate 72 and upper ends of the right and left end portions of the traybody 71 are the same as each other in position in the up and downdirection.

With this configuration, as illustrated in FIG. 12, the first platecontact portion of the plate 72 which is in contact with the first guidecontact portion 482 b of the first operation portion 48 and a secondplate contact portion of the plate 72 (a portion of the plate 72 at asecond contact position) which is in contact with the second guidecontact portion 492 b of the second operation portion 49 are locatedfarther from the hinges 77 than the engagement grooves 421 in the up anddown direction. With this arrangement of the first plate contact portionand the second plate contact portion, the plate 72 can be moved usingthe principle of leverage even by a small operating force applied to thefirst operation portion 48 or the second operation portion 49.

That is, in the fourth embodiment, the first guide engagement portion442 is located between the third hinge mechanism and the first platecontact portion of the plate 72 which is in contact with the first guidecontact portion 482 b, and the second guide engagement portion 452 islocated between the third hinge mechanism and the second plate contactportion of the plate 72 which is in contact with the second guidecontact portion 492 b. As a result, a distance between the pivot centerof the plate 72 and each of the first plate contact portion and thesecond plate contact portion is long. Thus, the engaged state of theplate 72 can be canceled using the principle of leverage by a smalloperating force applied to the first operation portion 48 or the secondoperation portion 49.

The present embodiment employs the first operation portion 48 and thesecond operation portion 49 used in the first embodiment but may employthe first operation portion 58 and the second operation portion 59 usedin the second embodiment or the first operation portion 68 and thesecond operation portion 69 used in the third embodiment.

Fifth Embodiment

FIG. 13 illustrates a sheet tray 8 according to a fifth embodiment. FIG.14 illustrates a plate 82. The following description is provided onlyfor a difference between the sheet tray 8 according to the fifthembodiment and the sheet tray 7 according to the fourth embodiment.Also, the same reference numerals as used in the fourth embodiment areused to designate the corresponding elements of the fifth embodiment,and an explanation of which is dispensed with.

The sheet tray 8 according to the fifth embodiment is different from thesheet tray 7 according to the fourth embodiment in that the plate 82 hasan L-shape and that no urging members are attached to the hinges 77 inthe fifth embodiment. As illustrated in FIG. 14, the plate 82 includes afirst plate portion 821 extending in the up and down direction and asecond plate portion 822 extending in the front and rear direction. Thefirst plate portion 821 and the second plate portion 822 are formedintegrally with each other so as to have an L-shape in side view. Thefirst plate portion 821 and the second plate portion 822 have the samethickness and the same length in the right and left direction. Thelength of the second plate portion 822 in the front and rear directionis greater than that of the first plate portion 821 in the up and downdirection. The hinges 77 are provided at an intersection of the firstplate portion 821 and the second plate portion 822.

In a use state in which the sheet tray 8 is mounted on the image formingapparatus 1, as illustrated in FIG. 14, a center-of-gravity position Gof the plate 82 is located on one of opposite sides of the hinges 77which is nearer to the second plate portion 822. Thus, a rotation momentdue to the weight of the plate 82 acts on the plate 82 in a direction inwhich the second plate portion 822 moves downward in the verticaldirection. That is, the rotation moment is generated in the direction inwhich the second plate portion 822 rotates in the clockwise direction inFIG. 14. Thus, the plate 82 automatically pivots from the secondposition to the first position by the rotation moment generated by theweight of the plate 82. This configuration eliminates the need to usethe urging member for urging the plate 82 from the second position tothe first position.

It is noted that the plate used for the sheet tray 8 may have aconfiguration different from that of the plate 82 as long as a portionof the plate which is located on one side of the hinges 77 and whichdoes not include the engagement grooves 421 is heavier than a portion ofthe plate which is located on the other side of the hinges 77 and whichincludes the engagement grooves 421. For example, a weight is providedon a portion of the plate which is located on one side of the hinges 77and which does not include the engagement grooves 421.

That is, in the fifth embodiment, the center-of-gravity position at thefirst position of the plate is located on an opposite side of the pivotaxis of the third hinge mechanism from the first plate engaging portionand the second plate engaging portion in the horizontal direction in astate in which the tray body 71 is disposed such that the sheetconveying direction on the tray body 71 coincides with an obliquely downdirection.

Thus, in the case where the sheet tray is mounted on a rear surface ofthe image forming apparatus 1, appropriate design of thecenter-of-gravity position of the plate causes the plate toautomatically pivot from the second position to the first position dueto the rotation moment generated by the weight of the plate. Thisconfiguration eliminates the need to use the urging member for urgingthe plate.

The present embodiment employs the first operation portion 48 and thesecond operation portion 49 used in the first embodiment but may employthe first operation portion 58 and the second operation portion 59 usedin the second embodiment.

Sixth Embodiment

FIG. 15 illustrates a front-side configuration of a sheet tray 9according to the sixth embodiment. FIG. 16 illustrates a rear-sideconfiguration of the sheet tray 9 according to the sixth embodiment. Thesheet tray 9 according to the sixth embodiment is configured such thatthe same component is used for a first guide 94 and a second guide 95.The following description is provided only for a difference between thesheet tray 9 according to the sixth embodiment and the sheet tray 4according to the first embodiment. Also, the same reference numerals asused in the first embodiment are used to designate the correspondingelements of the sixth embodiment, and an explanation of which isdispensed with.

The sheet tray 9 according to the sixth embodiment is different from thesheet tray 4 according to the first embodiment in that a groove 911 isformed in a tray body 91, that the first guide 94 has a third guideengagement portion 942 and a third operation portion 948, and that thesame component is used for the second guide 95 and the first guide 94.

As illustrated in FIG. 15, the groove 911 is formed in a front surfaceof the tray body 91 near a lower end portion thereof. The groove 911 hassuch a depth that the third guide engagement portion 942 and a fourthguide engagement portion 952 are not engaged with the groove 911.

The third operation portion 948 and the third guide engagement portion942 are formed at a lower end portion of a first guide portion 941 ofthe first guide 94 so as to be symmetrical with the first operationportion 48 and the first guide engagement portion 442 with respect to aline that is parallel to the right and left direction and that extendsthrough a center of the first guide portion 941 in the up and downdirection. The same component is used for the third operation portion948 and the first operation portion 48, and the same component is usedfor the third guide engagement portion 942 and the first guideengagement portion 442.

The second guide 95 has a shape formed by rotating the first guide 94 by180 degrees along the front surface of the tray body 91. That is, thefirst guide 94 and the second guide 95 have the same shape and arearranged so as to be symmetrical with each other with respect to thecenter of rotation of the pinion gear 461. The second operation portion49 of the second guide 95 corresponds to the third operation portion 948of the first guide 94. The second guide engagement portion 452 of thesecond guide 95 corresponds to the third guide engagement portion 942 ofthe first guide 94.

A fourth operation portion 958 provided on a lower portion of the secondguide 95 corresponds to the first operation portion 48 of the firstguide 94. The fourth guide engagement portion 952 provided on the lowerportion of the second guide 95 corresponds to the first guide engagementportion 442 of the first guide 94. As illustrated in FIG. 16, the secondrack portion 454 of the second guide 95 corresponds to the first rackportion 444 of the first guide 94.

That is, in the sixth embodiment, the first guide 94 has the third guideengagement portion 942 and the third operation portion 948 located on anopposite side of the first rack portion 444 from the first guideengagement portion 442. The second guide 95 has a shape formed byrotating the first guide 94 by 180 degrees along a support surface 91 aof the tray body 91 for supporting the sheet. The second guideengagement portion 452 corresponding to the third guide engagementportion 942 is engaged with one of the engagement grooves 421.

Since the first guide 94 has the third guide engagement portion 942 andthe third operation portion 948, it is possible to provide commonalitybetween the first guide 94 and the second guide 95, resulting in lowermanufacturing cost and easier management of components.

Modifications

While the third hinge mechanism is used for pivotal movement of theplate in the above-described embodiments, the plate may be moved indifferent manners. For example, the plate may be translated instead ofthe pivotal movement.

The urging members 43 are attached to the hinges 47 or the hinges 77 inthe above-described embodiments, but positions and form of the urgingmembers 43 are not limited in particular as long as the urging members43 urge the plate from the second position toward the first position.Thus, use of the urging member enables the plate to be kept at the firstposition with a simple configuration.

The present disclosure is applied to the sheet tray mounted on the rearsurface of the image forming apparatus 1 in the above-describedembodiments but may be applied to the sheet cassette 3 except the fifthembodiment.

Effects

The sheet tray 4 according to the first embodiment includes the traybody 41 capable of supporting the sheet or sheets. The sheet tray 4includes the first guide 44 that is provided on the tray body 41 so asto be slidable in the widthwise direction and is brought into contactwith one edge of the sheet or sheets in the widthwise direction toposition the sheet or sheets to the predetermined position. The sheettray 4 includes the second guide 45 that is provided on the tray body 41so as to be slidable in the widthwise direction and is brought intocontact with the other edge of the sheet or sheets in the widthwisedirection to position the sheet or sheets to the predetermined position.The sheet tray 4 includes the interlocking mechanism 46 that enables theinterlocked sliding operations of the first guide 44 and the secondguide 45. The sheet tray 4 includes the plate 42 movably supported bythe tray body 41 and having the engagement grooves 421 as the examplesof the first plate engaging portion to be engaged with the first guide44 and the second plate engaging portion to be engaged with the secondguide 45. The first guide 44 includes: the first guide engagementportion 442 engageable with one of the engagement grooves 421; and thefirst operation portion 48 for moving the plate 42. The second guide 45includes: the second guide engagement portion 452 engageable with one ofthe engagement grooves 421; and the second operation portion 49 formoving the plate 42. When each of the first operation portion 48 and thesecond operation portion 49 is located at the non-operated position, theplate 42 is located at the first position at which the first guideengagement portion 442 is in engagement with one of the engagementgrooves 421, and the second guide engagement portion 452 is inengagement with one of the engagement grooves 421. When at least one ofthe first operation portion 48 and the second operation portion 49 islocated at the operated position, the plate 42 is located at the secondposition at which the first guide engagement portion 442 is spaced apartfrom the engagement grooves 421, and the second guide engagement portion452 is spaced apart from the engagement grooves 421.

With this configuration, when at least one of the first operationportion 48 and the second operation portion 49 is operated, the plate 42engaged with the first guide 44 and the second guide 45 is moved todisengage the plate 42 and each of the first guide 44 and the secondguide 45 from each other, thereby allowing the first guide 44 and thesecond guide 45 to slide. Accordingly, the user may operate any of thefirst operation portion 48 and the second operation portion 49 to slideboth of the first guide 44 and the second guide 45 to their respectivedesired positions, resulting in high usability.

In the sheet tray 4 according to the first embodiment, the firstoperation portion 48 includes the first moving portion 482 having thefirst guide contact portion 482 b that is in contact with the plate 42when the first operation portion 48 is located at the operated position.The second operation portion 49 includes the second moving portion 492having the second guide contact portion 492 b that is in contact withthe plate 42 when the second operation portion 49 is located at theoperated position.

With this configuration, when the first moving portion 482 or the secondmoving portion 492 is operated, the first guide contact portion 482 b orthe second guide contact portion 492 b contacts and pushes the plate 42to turn the plate 42, so that its engaged state is canceled. That is, itis possible to achieve the first operation portion 48 and the secondoperation portion 49 with a simple configuration.

In the sheet tray 4 according to the first embodiment, the firstoperation portion 48 includes the hinge 483 as the first hinge mechanismwhich supports the first moving portion 482 pivotably. The secondoperation portion 49 includes the hinge 493 as the second hingemechanism which supports the second moving portion 492 pivotably.

That is, the hinge mechanisms are used for moving the first movingportion 482 and the second moving portion 492. This configurationfacilitates designing.

In the sheet tray 5 according to the second embodiment, the firstoperation portion 58 includes the first sliding mechanism 583 thatsupports the first moving portion 582 slidably, and the second operationportion 59 includes the second sliding mechanism 593 that supports thesecond moving portion 592 slidably.

Sliding mechanisms are used for moving the first moving portion 582 andthe second moving portion 592, resulting in reduced amount of operationfor moving the first moving portion 582 and the second moving portion592.

In the sheet tray 4 according to the first embodiment, the plate 42 andthe tray body 41 are coupled to each other by the hinges 47 as the thirdhinge mechanism.

The configuration using the hinge mechanism for moving the plate 42facilitates designing.

In the sheet tray 4 according to the first embodiment, the first platecontact portion of the plate 42 which is in contact with the first guidecontact portion 482 b is located between the hinges 47 and the firstguide engagement portion 442, and the second plate contact portion ofthe plate 42 which is in contact with the second guide contact portion492 b is located between the hinges 47 and the second guide engagementportion 452.

This configuration can cancel the engaged state of the plate 42 with asmall amount of operation of the first operation portion 48 or thesecond operation portion 49.

In the sheet tray 7 according to the fourth embodiment, the first guideengagement portion 442 is located between the hinges 77 as the thirdhinge mechanism and the first plate contact portion of the plate 42which is in contact with the first guide contact portion 482 b, and thesecond guide engagement portion 452 is located between the hinges 77 andthe second plate contact portion of the plate 42 which is in contactwith the second guide contact portion 492 b.

With this configuration, the engaged state of the plate 42 can becanceled using the principle of leverage by the small operating forceapplied to the first operation portion 48 or the second operationportion 49.

In the sheet tray 8 according to the fifth embodiment, thecenter-of-gravity position G at the first position of the plate islocated on an opposite side of the pivot axis of the hinges 77 from theengagement grooves 421 in the horizontal direction in the state in whichthe tray body 71 is disposed such that the sheet conveying direction onthe tray body 71 coincides with the obliquely down direction.

With this configuration, in the case where the sheet tray 8 is amulti-purpose tray mounted on the image forming apparatus, appropriatedesign of the center-of-gravity position of the plate 82 causes theplate 82 to automatically pivot from the second position to the firstposition due to the rotation moment generated by the weight of the plate82. This configuration eliminates the need to use the urging member forurging the plate 82.

In the sheet tray 4 according to the first embodiment, the urgingmembers 43 are provided to urge the plate 42 from the second positiontoward the first position.

With this configuration, the plate 42 can be kept at the first positionby a simple configuration using the urging members 43.

In the sheet tray 4 according to the first embodiment, the interlockingmechanism 46 includes: the pinion gear 461 provided on the tray body 41;the first rack gear 444 a provided on the first guide 44 and engagedwith the pinion gear 461; and the second rack gear 454 a provided on thesecond guide 45 and engaged with the pinion gear 461.

That is, it is possible to achieve the interlocking mechanism 46 with asimple configuration.

In the sheet tray 9 according to the sixth embodiment, the first guide94 has the third guide engagement portion 942 and the third operationportion 948 located on an opposite side of the first rack gear 444 afrom the first guide engagement portion 442. The second guide 95 has ashape formed by rotating the first guide 94 by 180 degrees along thesupport surface 91 a of the tray body 91 for supporting the sheet. Thesecond guide engagement portion 452 of the second guide 95 whichcorresponds to the third guide engagement portion 942 of the first guide94 is engaged with one of the engagement grooves 421.

Since the first guide 94 has the third guide engagement portion 942 andthe third operation portion 948, it is possible to provide commonalitybetween the first guide 94 and the second guide 95, resulting in lowermanufacturing cost and easier management of components.

What is claimed is:
 1. A sheet tray, comprising: a tray body configuredto support a sheet; a first guide provided on the tray body so as to beslidable in a widthwise direction orthogonal to a sheet conveyingdirection in which the sheet is to be conveyed, the first guide beingcontactable with a first edge portion of the sheet in the widthwisedirection to position the sheet; a second guide provided on the traybody so as to be slidable in the widthwise direction and contactablewith a second edge portion of the sheet in the widthwise direction toposition the sheet; an interlocking mechanism configured to interlocksliding operations of the first guide and the second guide; and a platemovably supported by the tray body and comprising (i) a first plateengaging portion to be engaged with the first guide and (ii) a secondplate engaging portion to be engaged with the second guide, wherein thefirst guide comprises: a first guide engagement portion to be engagedwith the first plate engaging portion; and a first operation portionconfigured to move the plate, wherein the second guide comprises: asecond guide engagement portion to be engaged with the second plateengaging portion; and a second operation portion configured to move theplate, wherein when each of the first operation portion and the secondoperation portion is located at a non-operated position, the plate islocated at a first position at which the first plate engaging portion isengaged with the first guide engagement portion, and the second plateengaging portion is engaged with the second guide engagement portion,and wherein when at least one of the first operation portion and thesecond operation portion is located at an operated position, the plateis located at a second position at which the first plate engagingportion is spaced apart from the first guide engagement portion, and thesecond plate engaging portion is spaced apart from the second guideengagement portion.
 2. The sheet tray according to claim 1, wherein thefirst operation portion comprises a first moving portion comprising afirst guide contact portion being in contact with the plate when thefirst operation portion is located at the operated position, and whereinthe second operation portion comprises a second moving portioncomprising a second guide contact portion being in contact with theplate when the second operation portion is located at the operatedposition.
 3. The sheet tray according to claim 2, wherein the firstoperation portion comprises a first hinge mechanism supporting the firstmoving portion such that the first moving portion is pivotable, andwherein the second operation portion comprises a second hinge mechanismsupporting the second moving portion such that the second moving portionis pivotable.
 4. The sheet tray according to claim 2, wherein the firstoperation portion comprises a first sliding mechanism supporting thefirst moving portion such that the first moving portion is slidable, andwherein the second operation portion comprises a second slidingmechanism supporting the second moving portion such that the secondmoving portion is slidable.
 5. The sheet tray according to claim 4,further comprising a third hinge mechanism coupling the plate and thetray body to each other.
 6. The sheet tray according to claim 5, whereinthe plate is configured to pivot relative to the tray body about a pivotaxis via the third hinge mechanism, and wherein a direction of the pivotaxis substantially coincides with a direction of a line connectingbetween a position at which the first guide engagement portion and thefirst plate engaging portion are engaged with each other and a positionat which the second guide engagement portion and the second plateengaging portion are engaged with each other.
 7. The sheet trayaccording to claim 5, wherein the plate comprises a first plate contactportion that is a portion of the plate which is contacting the firstguide contact portion of the first guide, and the first plate contactportion is located between the third hinge mechanism and the first guideengagement portion, and wherein the plate comprises a second platecontact portion that is a portion of the plate which is contacting thesecond guide contact portion of the second guide, and the second platecontact portion is located between the third hinge mechanism and thesecond guide engagement portion.
 8. The sheet tray according to claim 5,wherein the first guide engagement portion is located between the thirdhinge mechanism and a first plate contact portion of the plate which iscontactable with the first guide contact portion of the first guide, andwherein the second guide engagement portion is located between the thirdhinge mechanism and a second plate contact portion of the plate which iscontactable with the second guide contact portion of the second guide.9. The sheet tray according to claim 5, wherein a center-of-gravityposition of the plate located at the first position is located on anopposite side of the first plate engaging portion and the second plateengaging portion from a pivot axis of the third hinge mechanism in ahorizontal direction in a state in which the tray body is disposed suchthat the sheet conveying direction on the tray body coincides with anobliquely down direction.
 10. The sheet tray according to claim 1,further comprising an urging member configured to urge the plate fromthe second position toward the first position.
 11. The sheet trayaccording to claim 1, wherein the interlocking mechanism comprises: apinion gear provided on the tray body; a first rack provided on thefirst guide and engaged with the pinion gear; and a second rack providedon the second guide and engaged with the pinion gear.
 12. The sheet trayaccording to claim 11, wherein the first guide comprises a third guideengagement portion and a third operation portion located on an oppositeside of the first rack from the first guide engagement portion, andwherein the second guide is a guide obtained by rotating the first guidesuch that the third guide engagement portion serves as the second guideengagement portion to be engaged with the second plate engaging portion,and that the first rack serves as the second rack to be engaged with thepinion gear.
 13. An image forming apparatus, comprising: a sheet tray;and an image forming device configured to form an image on a sheet,wherein the sheet tray comprises: a tray body configured to support thesheet; a first guide provided on the tray body so as to be slidable in awidthwise direction orthogonal to a sheet conveying direction in whichthe sheet is to be conveyed, the first guide being contactable with afirst edge portion of the sheet in the widthwise direction to positionthe sheet; a second guide provided on the tray body so as to be slidablein the widthwise direction and contactable with a second edge portion ofthe sheet in the widthwise direction to position the sheet; aninterlocking mechanism configured to interlock sliding operations of thefirst guide and the second guide; and a plate movably supported by thetray body and comprising (i) a first plate engaging portion to beengaged with the first guide and (ii) a second plate engaging portion tobe engaged with the second guide, wherein the first guide comprises: afirst guide engagement portion to be engaged with the first plateengaging portion; and a first operation portion configured to move theplate, wherein the second guide comprises: a second guide engagementportion to be engaged with the second plate engaging portion; and asecond operation portion configured to move the plate, wherein when eachof the first operation portion and the second operation portion islocated at a non-operated position, the plate is located at a firstposition at which the first plate engaging portion is engaged with thefirst guide engagement portion, and the second plate engaging portion isengaged with the second guide engagement portion, and wherein when atleast one of the first operation portion and the second operationportion is located at an operated position, the plate is located at asecond position at which the first plate engaging portion is spacedapart from the first guide engagement portion, and the second plateengaging portion is spaced apart from the second guide engagementportion.